Pathology Lesson 2: Cellular Reaction to Injury & Structural Abnormalities and Birth Defects

What is the definition of metaplasia?

A reversible change in cell structure from one fully different form to another form in response to a normal or abnormal stimulus.

Is metaplasia considered a reversible or irreversible change?

Reversible.

How is physiological metaplasia defined?

A normal type of cell maturation.

How is pathological metaplasia defined?

A change due to abnormal stimulus.

What type of epithelium lines the ectocervix?

Squamous epithelium.

What is the example of pathological metaplasia provided for smokers?

A change in the respiratory epithelium.

What is the initial cell type of the respiratory epithelium before metaplasia in smokers?

Ciliated columnar epithelium.

The harsh stimulus from cigarette smoke initiates a change from ciliated columnar epithelium to which cell type?

Squamous epithelium.

Is metaplasia itself considered a malignant change?

No, it is initially a benign change where the cell simply changes its structure in response to abnormal stress.

What two conditions can develop from prolonged exposure to the abnormal stimulus that caused metaplasia?

Dysplasia and later a neoplasm.

What are the two main processes through which cell death occurs in a multicellular organism?

Necrosis and apoptosis.

What causes necrosis to occur in a cell?

Exposure to extreme conditions, harmful environments, injury, toxins, increased temperature, or decreased oxygen levels.

How is apoptosis defined in the transcript?

A pre-planned regular process of cell death occurring in the body where the cell itself actively takes part in its own death.

According to the lecture, what is the shelf life of red blood cells before they are destroyed?

$120$ days.

Failure of cells to die on time through apoptosis can lead to which conditions?

A tumour or cancer formation.

What diseases can result if cells die too fast through the process of apoptosis?

AIDS, heart disease, and liver disease.

What structural changes occur in the cell wall during necrosis?

There is a loss of integrity of the wall of the cell, leading to swelling of the cell's contents.

How do the structural changes in apoptosis differ from those in necrosis?

In apoptosis, there is no disintegration of the cell membrane or wall; instead, there is a shrinkage of cellular contents along with clumping of the membrane.

What are the condensed bodies formed during apoptosis called?

Apoptotic bodies.

How does the immune system handle apoptotic bodies?

They are recognised by the immune system and destroyed efficiently by the immune cells, resulting in no inflammatory reaction.

Is necrosis considered an active or passive process?

It is a passive process which does not require energy and can occur at any point of time.

Why is apoptosis described as an active process?

It requires energy and occurs in an organised manner using many enzymes and agents to carry out the process.

What are the pathological consequences of necrosis in the body?

Inflammation, tissue damage, and the accumulation of cellular debris.

What is the defining characteristic of the event of necrosis compared to apoptosis?

Necrosis is a random, unregulated event caused by uncontrolled external factors, while apoptosis is a predefined cell suicide.

What is the primary necessity of apoptosis for the human body?

It is a natural physiological process required to maintain a balance in the number of cells for smooth functioning of the body.

What is the definition of amelia?

The absence of one or more limbs.

What does the term aplasia refer to?

A complete failure of a tissue or an organ to develop.

What is focal milia?

A congenital condition in which the proximal portions of the limbs are poorly developed or absent.

What is the term for having more than the normal number of fingers and toes?

Polydactylism

Which structural abnormality results from the failure of the fetus spine to close properly during the first month of gestation?

Spina bifida

What are common physical characteristics of infants born with spina bifida?

An open lesion on the spine and damage to the nerves and spinal cord.

What bowel and bladder complications can develop as a result of spina bifida?

Complications that arise as the children age due to nerve and spinal cord damage.

What is the medical term for the accumulation of excessive amounts of cerebrospinal fluid in the brain?

Hydrocephalus

Define cleft lip.

A separation of the two sides of the lip, which may include the bones of the upper jaw or maxillae.

What is the name of the upper jaw bone that may be affected by a cleft lip?

Maxillae

According to the American Cleft Palate Craniofacial Association 2020, how many children are born with cleft lip or cleft palate in the US each year?

About $7,000$ children.

How is a cleft palate defined?

A condition where the two sides of the palate fail to fuse during fetal development, resulting in an opening between the palatine bones.

What part of the mouth do the palatine bones form?

The roof of the mouth.

What is the primary factor identified as causing the majority of clefts?

Genetic factors

What are the three main components of treatment for cleft lip and cleft palate?

Surgery, dental orthodontic care, and speech therapy.

What does the term color blindness or color deficiency refer to?

A condition in which individuals have difficulties identifying the various colors and shades of colors.

Color blindness is due to defects in which specialized cells of the retina?

Cones

In humans, what is the specific function of the cones in the eye?

They enable humans to see in color.

Describe the condition of red-green color blindness.

Individuals can distinguish colors when side by side but cannot determine if a color is red or green when shown only one of the two.

What occurs in the case of blue color blindness?

Individuals cannot distinguish between blue and yellow and instead see only white or gray.

What is achromatopsia?

The total color blindness, which is extremely rare and hereditary.

What is the visual limitation for individuals with achromatopsia?

They cannot see any colors and are limited to black and white or shades of gray.

Besides total color loss, what are two other results of achromatopsia?

Poor visual acuity and extreme sensitivity to light.

Which demographic is almost exclusively affected by inherited color blindness?

Males

List three diseases mentioned that can lead to color blindness.

Alzheimer's disease, diabetes, and glaucoma.

Name three additional systemic or blood-related diseases that can lead to color blindness.

Leukemia, liver diseases, and sickle cell anemia.

Which neurological/muscular diseases are factors in color blindness?

Multiple sclerosis and Parkinson's disease.

Which specific types of medications can be factors in developing color blindness?

Antibiotics, barbiturates, and anti-tuberculosis drugs.

Apart from specific drug types, treatments for which medical issues are listed as factors in color blindness?

High blood pressure, nervous disorders, and psychological problems.

Identify chemical causes that can result in color blindness.

Carbon monoxide, carbon disulfide, fertilizers, styrene, and some lead-based chemicals.

Is there a treatment for inherited color blindness?

There is no treatment for it.

What is the status of acquired color blindness?

It could just be temporary.

What is another name for a vascular nevus birthmark?

Strawberry mark

What is the physiological cause of a vascular nevus?

A superficial blood vessel enlargement.

What are the typical colors of a vascular nevi?

Red or purple color.

Where on the body do vascular nevi typically appear?

The face, head, neck, and arms.

Who is Down syndrome named after?

J Langdon Down, a nineteenth-century British physician.

What is the alternate name for Down syndrome?

Trisomy $21$

Why is the alternate name for Down syndrome trisomy 21?

Because people with Down syndrome have an extra chromosome, usually number $21$ or $22$.

What is the typical total number of chromosomes in a healthy human?

$$46$$

In a healthy human, how many chromosomes come from the male sperm and female egg respectively?

$23$ from the male sperm and $23$ from the female egg.

Down syndrome is primarily characterized as a result of what biological process?

Genetic mutation

What environmental factor has Down syndrome been linked to?

It has not been related to environmental factors; it has been linked to the mother's age.

According to the National Institute of Child Health and Human Development, what is the chance of a 30-year-old mother having a baby with Down syndrome?

Less than $1$ in a $1,000$ chance.

What is the chance of a mother over the age of 49 having a baby with Down syndrome?

A $1$ in $12$ chance.

List three facial or head features of Down syndrome mentioned in the transcript.

Sloped forehead, flat nose or absent bridge, and low set ears.

What specific feature is found around the iris of the eyes in Down syndrome?

Gray or light yellow spots.

What are the characteristics of the hands in a person with Down syndrome?

Short broad hands with a single palmar crease.

Identify the most common fatal genetic disease in the United States.

Cystic fibrosis

According to the Cystic Fibrosis Foundation, how many people in the US have the disease?

About $30,000$ people.

Mutations in which regulator gene cause cystic fibrosis?

Cystic fibrosis transmembrane regulator gene.

What is the average age of death for the terminal disease cystic fibrosis?

An average age of $20$.

The defective cystic fibrosis gene prevents cells from releasing which ion?

Chloride

What is the direct consequence of the lack of chloride in the cells of cystic fibrosis patients?

A salt imbalance in the cells.

What type of substance do the defective cells in cystic fibrosis produce?

A thick and sticky mucus.

How does the thick mucus affect the respiratory system in cystic fibrosis?

It clogs the lungs and leads to infection.

What abdominal organ is blocked by mucus in cystic fibrosis?

The pancreas

How does the thick mucus in cystic fibrosis interfere with digestion?

It stops digestive enzymes from reaching the intestine.

Which medical condition is frequently found in cases of cystic fibrosis?

Diabetes mellitus

What is the meaning of SIDS?

Sudden infant death syndrome

According to the CDC, how many babies die suddenly and unexpectedly each year?

About $3,500$ babies.

What causes are included under sudden unexpected infant deaths?

Accidental suffocation in a sleeping environment and other deaths from unknown causes.

Is SIDS considered a result of a structural abnormality?

No, it is an idiopathic disorder.

What are alternative names for SIDS?

Cot death or crib death.

Why must funeral service practitioners understand SIDS?

To avoid stigmatizing families, as SIDS is not due to child abuse or neglect.

What components are typically included in a SIDS death investigation?

An autopsy, death scene investigation, review of the infant's health status, and family medical histories.

During what age range do most SIDS deaths occur?

Between the ages of $2$ and $4$ months.

What sleeping position is a known risk factor for SIDS?

Prone position (on the stomach).

Name two maternal risk factors for SIDS during or after pregnancy.

Smoking during pregnancy and exposure to secondhand smoke after birth.

List three soft surfaces that are risk factors for an infant's sleep environment.

Mattresses, sofas, and cushions.

Which infant gender has been identified as a risk factor for SIDS?

Male

Where do all cells exist according to Chapter 2?

within an environment

What occurs within the environment of a cell that leads to internal results?

changes

What is the result of environmental changes regarding a cell?

they result within that cell

What type of cellular change is paired with pathological changes in the lecture?

physiological changes